The 2014 Environmental Performance Index (EPI) ranks 178 countries on how well they perform on high-priority environmental issues in two broad policy areas: protection of human health from environmental harm and protection of ecosystems. Here we provide an overview of the top five and bottom five performers.

Top Five1. SwitzerlandSwitzerland is the top performer on the 2014 EPI, with high marks in Biodiversity and Habitat Protection, and Climate and Energy. For centuries, Switzerland had only one designated protected park area; over the past five years, however, officials introduced 15 new regional parks, with two additional national park projects underway. With this surge in park development, Switzerland achieved the highest possible score for protected terrestrial areas - significantly higher than those of neighboring countries France, Italy, and Austria. In terms of climate change, Switzerland has substantially reduced the carbon intensity of its economic growth, with over half its domestic electric production from hydropower plants and another 40 percent from nuclear. The country is also committed to reducing the carbon intensity of its economy, and is doing so at a substantially faster rate than Germany, France, Austria or Italy. In 2000, Switzerland passed a CO2 Act stipulating that energy-based CO2 emissions be reduced by 10 percent below 1990 levels between 2008 and 2012. In 2013, it reset the goal to at least 20 percent below 1990 levels by 2020. Switzerland is reducing both its Trend in Carbon Intensity and its Change in Trend in Carbon Intensity at the same time with an overall rank of 7 in the Climate & Energy policy category.

2. LuxembourgAt roughly $114,232 USD per capita, Luxembourg is the second richest country in the world with one of the smallest populations of all European Union countries. As a wealthy country, Luxembourg performs well on environmental health indicators, providing 100 percent Access to Drinking Water and Access to Sanitation. It also has achieved the international target of protecting 17 percent of terrestrial habitats - a goal designated in the Convention on Biological Diversity. Luxembourg has prided itself on its longstanding fulfillment of sustainable development criteria. Officials approved a domestic National Plan for Sustainable Development in 1999 and a second version of the plan was ratified in November 2010. Between the first and second plans, policymakers created indicators for sustainable development (there are currently 29) and related implementation laws. However, Luxembourg performs only moderately well in Climate and Energy, despite adopting a Kyoto Protocol target to reduce greenhouse gas emissions 72 percent of 1990 levels between 2008 and 2012. While the country has established a program to subsidize renewable energy, it still has a ways to go to de-carbonize its electricity generation sector.

3. AustraliaWith perfect or excellent target scores in many policy categories, Australia achieved the highest rank of all the G20 countries - likely the result of Australia's robust environmental protection and conservation policies. However, the country has much room for improvement in both the Fisheries and Climate and Energy categories. Australia's fish stocks - mainly the school shark, bigeye tuna, and the critically endangered bluefin tuna - are highly (15 percent) collapsed and overexploited in the Exclusive Economic Zone, with no plan is in place to suspend fishing or restore the depleted and collapsed stocks. Australia also performed poorly in Climate and Energy; its reliance on coal makes it the second-highest emitter of CO2 per GDP among all OECD countries. However, the country is now taking actions on climate and energy, legislating and implementing a concrete carbon tax scheme.

4. SingaporeAs a small island nation with a population of over 5 million but a land area of only 671 square kilometers, Singapore has been forced to focus on efficient resource consumption and reuse. Given its limited geography, Singapore has undertaken robust, integrated and long-term land use planning measures and is a recognized, international leader on sustainable development. Created in 2009, the Sustainable Singapore Blueprint set a number of environmental targets for the country to meet by 2030, including an ambitious goal of recycling 70 percent of its waste within that time horizon. The city-state's performance on Wastewater Treatment, Access to Drinking Water, and Sanitation speaks to the potential of urban infrastructure to secure key elements of environmental health. Singapore scores 99.65 out of 100 for Wastewater Treatment. The world average, meanwhile, is 24.87. Notably, among the top 10 ranked countries, Singapore is also the top performer in Climate and Energy. However, the country is one of the worst performers on Fisheries, receiving a score of zero.

5. Czech Republic Mostly surrounded by mountains, the Czech Republic maintains impressive protection for public lands. Nearly 14 percent of the country is designated a protected landscape area, and 1.52 percent is designated a national park. As a result of these policies, along with an article in its constitution that ensures "the protection of natural resources," the Czech Republic scores high in Biodiversity and Habitat Protection, ranking 13th in the world. However, the country suffers from poor air quality. Average exposure to harmful particulate matter is very high - the Czech Republic ranks 162nd in average exposure to fine particulate matter (PM2.5, air pollutants that can penetrate human lung and blood tissue). Poor air quality could be a reason why the country has highest cancer rates in the European Union.

Bottom Five174. AfghanistanAfghanistan - ranked for the first time in the 2014 EPI - faces numerous environmental challenges. In Biodiversity and Habitat Protection, the country receives nearly the worst scores for terrestrial habitat protection, and a score of 0 out of 100 for critical species protection. Nearly 150 species of mammals and birds are listed at risk, but illegal poaching and hunting seems to be getting worse. Ongoing conflicts in the country certainly pose challenges to effective governance; however, a few signs of hope indicate that Afghanistan will improve its performance in the future. The percentage of households with access to clean drinking water went from 5 percent in 1991 to 61 percent in 2011. The Child Mortality score has also vastly improved, with a 38-percent improvement over the last decade.

175. LesothoNearly two-thirds of the small African country's income is derived from the agricultural sector, making natural resource management key to the country's economic well-being. However, policy implementation is challenging due to capacity gaps at the individual and institutional levels. While Lesothos's Environment Act of 2008 formally "make(s) provision for the projection and management of the environment and conservation and sustainable utilization of natural resources," the benefits of such policies are not fully realized. Because Lesotho's economy is highly resource dependent, one of the biggest sustainable development challenges for the country is addressing the poverty associated with land degradation caused by overexploitation and erosion. Lesotho scores poorly on the overall EPI due to poor Access to Drinking Water and Access to Sanitation, a high rate of deforestation, and very low levels of habitat and biodiversity protections. The UN Development Programme continues to work closely with the government of Lesotho on a variety of projects, including rural electrification through pilot solar installation programs and developing a sustainable land management model to address governance challenges.

176. HaitiHaiti's low position at 176 is no surprise, given its history of political instability and poverty. Under chaotic political circumstances formulating -- and enforcing -- effective policies is difficult. A lack of land and conservation planning has led large numbers of Haitians to move onto floodplains and other marginal lands, where they face increased risk of dysentery, malaria, tuberculosis, and other sanitation-related diseases. The country scores near the bottom of the Water and Sanitation category, with only 26 percent of the population having access to sanitation and 64 percent, access to drinking water. These environmental challenges are exacerbated by the fact that Haiti is by far the poorest country in the Western hemisphere, with 80 percent of the population living under the poverty line and 54 percent in abject poverty. Most Haitians lack access to modern energy services, instead relying on wood and charcoal as their primary fuel sources, leading to deforestation, soil erosion, and poor biodiversity and habitat protections. In addition, many Haitians depend upon non-commercial fishing for food, and impoverished local fishermen knowingly overexploit fish stocks to feed their families, which explains the country's poor Fisheries performance. Until 2013, Haiti -- with the second-longest coastline in the Caribbean -- was the only Caribbean country without marine protected areas where fishing was restricted.

177. MaliMali has the highest child mortality rate of any country in the 2014 EPI. The high rates of child mortality, which measure the probability of death between a child's first and fifth birthdays, are largely the result of malaria and malnutrition. While the Malian government is not responsible for the presence of malaria-bearing mosquitoes, it could be doing much more to invest in prevention. In general, Mali's failure to sufficiently invest in environmental protection is the primary reason for its wide array of environmental problems. Unlike many of its neighbors, Mali has experienced rapid economic growth along with political and social stability over the past two decades. However, this stability and rise from the lowest levels of poverty has not been coupled with necessary investments in sustainability. Although Mali's government is relatively well-funded for a developing country, in recent years it has only spent 1-2 percent of its non-interest public spending on activities related to environmental protection. Fortunately, the Malian government has recently acknowledged the importance of its environment, and has made initial steps toward greater sustainability investments.

178. SomaliaSomalia receives the unfortunate position as worst performer in the 2014 EPI. The abysmal ranking offers a classic example of environmental destruction playing out in the absence of a government capable of enacting and enforcing environmental policies. Somalia has been embroiled in civil war since 1991, and for more than two decades following the breakout of the war it lacked a formal parliament. This absence of a functioning government has had significant consequences for local ecosystems, including a ranking of 172 for Biodiversity and Habitat Protection. The Somali population, largely impoverished and persistently threatened by armed conflict, has been focused on short-term survival, resorting to widespread tree cutting and charcoal burning. These activities have reduced forest cover to less than 200 sq. km of forested land and worsened air pollution, particularly for Household Air Quality in which the country ranks 163rd. Somalia's coastal ecosystems have also faced significant destruction in the absence of environmental regulation. Foreign fishing vessels operate at will in Somali waters, over-exploiting fish stocks and harming coral reefs, leading to scores of 0 for both Fisheries indicators in the EPI. Most troubling, however, is the absence of public infrastructure that has meant a lack of functioning water supply systems. Somalians withdraw drinking water from wells which are not fit for human consumption, which explain a last-place ranking on Access to Drinking Water.

Fortunately, there are signs of hope. In 2012, Somalia established its first permanent central government since the start of the civil war, and with the support of Kenya, Ethiopia and the United States, this government has been gradually consolidating and expanding its territorial control. As this process unfolds, the Somali government may gradually develop the authority and the capacity to protect the environment and human health.